Acrobat opens in two different ways: on its own, as a standalone application, and in a web browser. The associated work areas differ in small but important ways.
The Acrobat work area includes a document pane that displays PDFs and a navigation pane on the left side that helps you browse through the current PDF. Toolbars near the top of the window provide other controls that you can use to work with PDFs.
View the work area for PDFs open
in the application
View the work area for PDFs open
in a web browser